It is a common that with money out, there is money in. When you spend money on ads then you get money back in form of sales and orders to your product. There some other ways to grow your business as well which might come in cheaper.
Everyday, thousands of businesses are created and enter the market to compete with you. This however should not make you hesitant to compete with them as well. But competition is a big words to describe this, you rather get yourself into a market that many businesses share the same interests and goals as you do.